Conventionally, a linerless label has been developed that lacks a release paper (i.e., a liner) temporarily attached to a back surface side of an adhesive agent layer of a label. Accordingly, a linerless label is thought to be desirable as a resource-saving material because a liner does not need to be disposed of after usage thereof.
FIG. 13 shows a perspective view of one embodiment of a conventional linerless label 1 wound into a rolled shape. The linerless label 1, as partially indicated in an enlarged cross-sectional view in FIG. 13, includes a label substrate 2; an adhesive agent layer 3 of a back surface side; a thermosensitive color developing agent layer 4 of a front surface side; and a transparent release agent layer 5 of an upper layer side.
A position detection mark 6 is pre-printed on the label substrate 2 of the back surface side. In addition, fixed information (not shown) such as a design may be pre-printed on a front surface side of the label substrate 2 where necessary, in addition to a label user mark or name.
The linerless label 1 may be provided as a single leaf label piece 1A by cutting at a pre-calculated pitch on an intended cutting line 7.
FIG. 14 shows a schematic side view of a thermal printer 8 into which a linerless label 1 is loaded for printing variable information such as merchandise information such as a price or a barcode of merchandise or administrative information relating to a product or a service, where appropriate. The thermal printer 8 includes a supplier 9 of the linerless label 1; a guide member 10; a detector 11; a printing part 12; and a cutter 13.
The supplier 9 holds the linerless label 1 into a rolled shape, and the supplier 9 may feed out the linerless label 1 into a belt shape in a direction of the guide member 10, the detector 11, the printing part 12 or the cutter 13.
The guide member 10 includes a guide roller 14. The guide member 10 is able to guide the fed out linerless label 1 in a direction of the detector 11 or the printing part 12.
The detector 11 includes a location detection sensor 15. The detector 11 may detect a relative location of the linerless label 1 (label piece 1A) with respect to the printing part 12, by detecting the position detection mark 6 on the back surface side of the linerless label 1.
The printing part 12 includes a thermal head 16 and a platen roller 17 (elastic roller). The linerless label 1 is sandwiched between the thermal head 16 and the platen roller 17 via a predetermined printing pressure, the platen roller 17 is rotatably driven at a constant speed, and a thermosensitive color developing agent layer 4 develops color by a supply of printing data to a thermal head 16. Accordingly, predetermined variable information may be printed onto the linerless label 1 (label piece 1A).
The cutter 13 includes a fixed blade 18 and a movable blade 19. A printed linerless label 1 that has been fed between the fixed blade 18 and the movable blade 19 is cut at the intended cutting line 7 according to a preset pitch, and a label piece 1A is issued and ejected.
A roller composed of an elastic body such as a rubber material may be used in the platen roller 17 for feeding and printing the linerless label 1 in the abovementioned construction of the thermal printer 8. In order to prevent attachment by the adhesive agent of the adhesive agent layer 3, a platen roller 17 is formed that is composed of an adhesive agent made of silicone rubber material that prevents the attachment of the adhesive agent, or a silicone oil or the like is applied onto an outer peripheral surface of the platen roller 17.
However, it is difficult to completely prevent attachment of the adhesive agent during a long period of usage. The linerless label 1 that passes through the platen roller 17 may become attached to the platen roller 17 and rolled up (see, imaginary line in FIG. 14). Accordingly, the label can become stuck, which may interfere with normal feeding of label 1, printing, and the issuance of the label piece 1A.
In addition, in a case where printing and issuance ceases with the linerless label 1 sandwiched between the thermal head 16 and the platen roller 17, the linerless label 1 does not readily peel away from the platen roller 17, and thus the linerless label 1 may be easily rolled up (similar to that mentioned above).
Thus, typical maintenance such as an operation that cleans an outer peripheral surface of the platen roller 17 or an operation that exchanges the platen roller 17, or the like, must be repeated. Accordingly, there has been a need for the platen roller 17 (elastic roller) allowing stable feeding and printing over an extended period of time.
Moreover, in addition to the platen roller 17, there has also been a need for an elastic roller for a label superior in an anti-stick property or a release property, even as a roller for simple guidance of linerless label 1 such as the guide roller 14, or a nip roller (not shown in the figures) comprising a pair of rollers that are rotatably driven to feed the linerless label 1 or a roller, where appropriate for a construction of a printer.
Further, there has also been a need for an elastic roller for a label that can stably feed a loaded linerless label 1 or loaded typical label with a liner.
While attempts have been made to form a groove or the like on an outer surface of the platen roller 17 in order to avoid an attachment phenomenon resulting from the adhesive agent layer 3 by decreasing a contact surface area between the linerless label 1 (the adhesive agent layer 3) and the platen roller 17, the contact surface area between the back surface of the liner of the label and the platen roller 17 is insufficient, and thus unable to exert the required frictional force (gripping force) between the liner and the platen roller 17 at a time of feeding and printing of a label with a liner. Accordingly, a problem arises that a stable feeding or a printing action cannot be expected due to deterioration in a feeding function such as slippage of a label.
In addition, a groove or the like that is formed on the platen roller 17 may also be easily worn down.
Similar to the abovementioned linerless label 1, the abovementioned various problems may occur even in a case where feeding or guiding a belt-shaped member of a paper or a film base including an adhesive agent or layer a bonding agent layer on the back surface side, and thus there is a need for an elastic roller superior in an anti-stick property or a release property.
It has been proposed to cover an outer layer of an inner layer elastic material member with a silicone resin having specified hardness in order to solve various problems mentioned above.
In other words, providing a coating layer composed of a silicone resin having low hardness (spring type hardness tester Asker C in accordance with SRIS 0101, hereinafter referred to as “C hardness”), allows the silicone resin to have both a non-stick property or a release property with respect to the adhesive agent layer and the frictional force (gripping force) and anti-wear property necessary with respect to the belt-shaped member as a result of a gelated resin having low hardness (C hardness of 20° C. or lower).
Accordingly, a belt-shaped member such as the linerless label and the typical label with a liner may be stably fed and guided.
With respect to the thermal printer 8, while models such as a two-inch model, a four-inch model, a six-inch model, or the like, have been designed in accordance with the width of the belt-shaped member to be printed thereon and issued, printing and issuing may be accomplished by replacing a plurality of belt-shaped members (e.g., linerless label 1) having a different width using one thermal printer 8.
In the thermal printer 8, while the elastic roller (platen roller 17) is assembled in accordance with the belt-shaped member having the widest design. In a case where a one-inch wide narrow-width linerless label 1 is loaded in the six-inch model thermal printer 8, approximately five inches are left by deducting one-inch width of the linerless label 1 from a six-inch width, and the platen roller 17 and the thermal head 16 are brought into contact in the five inches width. The platen roller 17 has sufficient gripping force to feed the belt-shaped member. Thus, in a case where the contact width of the platen roller 17 and the thermal head 16 is broadened, the load caused by friction is increased and accurate feeding of a belt shaped member becomes difficult.
Further, it is known that the linerless label 1 is guided (i.e., feeding-to-one-side method) so as to be directed to a single-sided direction of the platen roller 17 of the thermal printer 8, and fed, as per a guidance system for the linerless label 1 in the thermal printer 8. Even in the thermal printer 8 of the above feeding-to-one-side method, printing and issuing may be accomplished by replacing a plurality of belt-shaped members (e.g., linerless label 1) having a different width. Similarly to the abovementioned case, in a case where the platen roller 17 and the thermal head 16 are in direct contact at a part where the platen roller 17 is exposed with respect to the linerless label 1, the load caused by friction is increased and accurate feeding of a belt shaped member becomes difficult.